<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="app"></div>
    <script src="../js/vue.js"></script>
    <script>
      Vue.createApp({
        template: `
           <div>
              <h1>{{counter}}</h1>
              <button @click="increment">+1</button>
              <button @click="decrement">-1</button>
           </div>
      `,
        data: function () {
          return {
            counter: 0,
          };
        },
        //定义方法
        methods: {
          increment() {
            this.counter++;
          },
          decrement() {
            this.counter--;
          },
        },
      }).mount("#app");
    </script>
  </body>
</html>
